The present invention relates to a device for regulating the light width of headlights for vehicles. The present invention also relates to a vehicle which is provided with the inventive device for regulating the light width of the headlights.
One of such devices is disclosed for example in the German patent document DE 23 33 983. This device has a sensor unit in the region of the front axle and in the region of the rear axle of the vehicle. The sensor unit detects at least indirectly the change of the position of the vehicle in the region of the front axle and the rear axle relative to a roadway. The sensor units are formed as ultrasound sensors including an emitter and a receiver. With the sensor, the ultrasound radiation is emitted to the roadway and detected by the receiver when the ultrasound radiation is reflected from the roadway. The ultrasound sensors are connected with an evaluating device which determines from the signals of the sensors the corresponding distance of the sensors and thereby the vehicle structure from the roadway. From the distance of the sensors at both axles, the evaluating device determines the inclination of the vehicle, and the adjusting devices which are associated with the headlights are controlled by the evaluating device so that the light width of the headlight is maintained at least approximately constantly independently from the inclination of the vehicle. The disadvantage of this known device for regulating the light width is that the operation of the ultrasound sensor units is distorted with certain roadway properties and/or weather conditions, and thereby incorrect adjustment of the light width of the headlight can not be excluded.